| Jeremy,
Points well made! I have been part of an ongoing discussion of uniform grading systems on another forum. Given all the parameters they are difficult things to construct.
Wondered how you viewed the suggestions made in my book that the outline of the light source (bulb) is a good touchstone for grading luster without samples?
I agree that different pearl species would have to have relatively different standards, that is, in orient (overtone) some species such as Tahitian black (pinctada Margretifera) have it in abundance whereas pearls from the Maxima oyster seem generally devoid of that quality except in the case of very fine examples. |